We don’t know for sure.

We’re not even sure of its origin. Some say it was first published in London around 1765, but some argue that it could be from the previous century based on the archaic language and rhymes used in it.

If it was indeed based on the myth of Hjúki and Bil, who were siblings – then Jack and Jill are siblings. There’s a myth that while Hjúki and Bil were by the well fetching a pail of water, they were captured by the Moon God, Mani, and were taken to the moon.

If it was indeed based on the story behind Jack and Jill Hill (actual name of a hill) in Kilmersdon, Somerset – then Jack and Jill are a couple. In this origin story, Jack and Jill were expecting a baby. Unfortunately, Jack died due to an accident on the hill while fetching water, and Jill died shortly after childbirth due to heartbreak. Apparently, “Jill” was originally spelled as “Gill” and to this day, the surname “Gilson” is still common in the Kilmersdon area, suggesting there’s some truth in the story. The village even made a plaque dedicated to Jack and Jill in 2020.

If you’re planning on discussing this with a child, maybe use the first one lol the second is tragic.